填空題()由神經(jīng)元的長軸突或長樹突及包在它外面的神經(jīng)膠質(zhì)細(xì)胞(少突膠質(zhì)細(xì)胞、施萬細(xì)胞又叫神經(jīng)膜細(xì)胞)構(gòu)成。